Hand-operable smoke jet generator



Nov. 22, 1960 w. A. ROBERTSON HAND-OPERABLE SMOKE JET GENERATOR Filed July 12. 1957 United States Patent C) HAND-OPERABLE SMOKE JET GENERATOR William Arthur Robertson, Rockford, 111., assignor to Design Engineers, a copartnership, Rockford, Ill.

Filed July 12, 1957, Ser. No. 671,484

11 Claims. (Cl. 126-595) This invention relates to a hand-operable smoke jet generator, especially designed and adapted for use by service and installation men in the air conditioning field, by janitors and maintenance men for detecting drafts, and by inventors and research and development men in checking gas or air flow, gas mixing, and so forth.

The principal object is to provide a small, light device, such as a workman can easily carry about in his pocket or in a tool box where it will be ready for immediate use when the need for it arises, the same having a nozzle at one end to direct the smoke jet where it is wanted, and a bulb at the other end disposed in the palm of the hand holding the device, handy for compression to generate the amount of smoke needed and discharge it with sufiicient force to reach the place where it will best serve its purpose.

The device is so designed that it can be loaded with a lighted cigarette quickly and easily, and the metallic outer shell or casing of the device always remains comfortable to handle, because it is shielded from the heat of the lighted end of the cigarette by a spaced inner metallic tube in which the cigarette is housed, mounted in the nozzle inserted in the outer end of said tube, and because the air used to support combustion and to form the smoke jet is passed through the space between the parts the full length thereof to cool the same before it finds its way through holes in the outer end of the tube to the cigarette to provide the draft through it.

The invention is illustrated in the accompanying drawing, in which Fig. 1 is a longitudinal section through a hand-operable smoke jet generator made in accordance with my invention;

Fig. 2 is an action picture of the device in operation for better illustration;

Fig. 3 is a fragmentary section, corresponding to a portion of Fig. l, but showing a modified or alternative construction;

Fig. 4 is a cross-section on line 4-4 of Fig. 3;

Fig. 5 is another section like Fig. 3, showing another modified or alternative construction, and

Fig. 6 is a cross-section on line 66 of Fig. 5.

Similar reference numerals are applied to corresponding parts throughout the views.

Referring to Figs. 1 and 2, a lighted cigarette is indicated at 7 set in a holder 8 provided in the reduced tapered neck portion 9 of a metallic closure plug 10, which has a press fit in the mouth of the metallic inner tube 11 housed in an outer cylindrical metallic shell or casing 12 which, as shown in Fig. 2, forms a handle used in directing the nozzle 13 on plug toward the place where the jet of smoke indicated at 14 is needed. A bulb 15 of rubber or other compressible resilient material is mounted with a tight friction fit on the reduced intermediate portion of neck 16 provided on the rear end of the casing 12 and has a check valve 17 in the 'other end thereof which closes outwardly and opens inwardly. a 'Thus, air enters the bulb after it has-been compressed and ice is allowed to expand again to its normal size and shape, the air being compressed when the bulb is compressed and being discharged into the casing 12 to flow lengthwise thereof through the annular space 18 between the parts 11 and 12 and enter the tube 11 through radial holes 19 provided in the wall thereof near the outer end. The air entering at 19 displaces air from the inner end of the tube through the cigarette 7, which is discharged through the orifice 20 of the nozzle 13 as part of the smoke jet 14. The lighted end 21 of the cigarette, of course, heats the adjacent wall of the tube 11, but, because of the annular air space 18 around the tube, the casing 12 is more or less insulated and is always comfortable to handle. Also, the flow of cooler air through space 18 helps to cool off both parts 11 and 12. A metallic closure plug 22 seals the inner end of tube 11 inwardly from the end and there are V-notches 23 cut in the end at evenly circumferentially spaced intervals to serve as air openings establishing communication between the annular air jacket space 18 and bulb 15, the metal 24 between these notches being bent outwardly for line contact at the edges with the bore of casing 12 to hold the inner end of tube 11 in centered relationship to the casing with minimum opportunity for heat transfer from the tube to the casing. The other end portion 25 of the tube 11 is flared to define a tapered seat for the tapered neck portion 9 of the plug 10, and it will be noticed that the latter has a shallow but fairly wide annular groove 26 provided therein in which a gasket ring 27 of silicon rubber is provided to seal the joint with only light pressure on the plug besides insuring that the plug will not drop out accidentally even though pressed in lightly. The compressibility of the rubber is also advantageous be} cause of the compensation it affords for runout in size in quantity production and the compensation for wear. Therubber also insulates the plug 10 from the inner tube so that heat is not transferred to the plug. The inner end of the inner tube is held against inward movement by line contact with the tapered end portion 28 of the casing 12. The inclined annular edge 29 defined on the outer end of flared portion 25 has the extremity of the casing 12 swedged inwardly over it, as indicated at 30, to complete the assembly of the tube 11 in casing 12, holding the tube 11 against endwise movement between the tapered portion 28 and swedged portion 30.

In operation, the device is held in one hand, as shown in Fig. 2, so that the nozzle 13 can be accurately directed toward the spot where the smoke is needed, while the bulb 15 is compressed to discharge the jet 14 toward the spot with sufiicient force and in sufficient volume to reach the spot with sufiicient smoke to do some real good in checking air flow, drafts, gas mixture, or the like. There are many other places and many other kinds of jobs where a hand-operable smoke jet generator is needed and especially a small, light device like that herein dis: closed, such as a workman can easily carry about inhis pocket or in a tool box where it will be ready forime mediate use when the need for it arises. It takes very little time to light and insert a cigarette in the holder 8 and then insert the holder in the mouth of the tubell. The knurling on the periphery of the plug 10 indicated at 31 in Fig. 2 enables more easily pressing the holder in tight enough sothat it is not apt to fall out or allow air to escape around it when the bulb 15 is compressed.

Referring to Figs. 3 and 4, the tube 11' is otherwise the same and corresponds to tube 11 in Fig. l and is closed at its inner end in the same way by a plug 22, but; as shown, has three evenly circumferentially spacedradial projections 32. of equal length defined by outwardly 'crimped V- shaped portions of the end of the. tube ranged to engage the tapered end portion 28 of thecasing both to center the tube 11 in casing 12 and limit endwise movement of the tube inwardly, while defining ample sized arcuate air openings 23 between the projections 32 for free air flow from bulb 15 into the jacket space 18 between, the tube 11' and casing 12. This construction may be used in lieu of that shown in Fig. 1 at 23 24.

Referring to Figs. 5 and 6, the tube 11 is otherwise the same as and corresponds to tube 11 in Fig, 1 and is closed at its inner end in the same way by a plug 22, but, as shown, has three evenly circumferentially spaced radial projections 32 of equal length defined by' the bending inwardly of the metal therebetween, as indicated at 33, the projections 32' engaging the taper 28 both to center the tube 11" and limit inward movement thereof, while defining ample sized air openings 23' between the projections for free air flow from bulb 15 into the jacket space 18 between the tube 11' and casing 12. This construction may be used in lieu of that shown in Fig. l at 23-24. It is believed the foregoing description conveys a good understanding of the objects and advantages of my invention. The appended claims have been drawn to cover all legitimate modifications'and adaptations.

I claim:

1. A device of the character described, comprising an elongated tubular casing adapted to be held in one hand, a manually compressible bulb of resilient material mounted on and adapted to deliver air under pressure to one end of said casing and having an outwardly seating check valve controlling its air intake and discharge, said check valve opening inwardly to admit fresh air into said bulb and closing outwardly upon compression of said bulb whereby to cause air flow in one direction into said casing from said bulb, an elongated, combustion chamber defining tube mounted inside said casing in spaced nonconducting relation thereto closed at its inner end and having an open outer end in sealed relationship a'nnularly thereof to the adjacent end of said casing, said 'tube having an air inlet opening in the Wall thereof, and a removable nozzle closing the open end of said tube and having a longitudinal bore defining a relatively restricted discharge orifice in the outer end portion thereof and an enlarged inner end portion communicating with said orifice and with the combustion chamber and defining a holder for one end portion of an elongated combustible material, such as a cigaret, for insertion of one end of the combustible material to be supported by and to extend inwardly from said holder into the combustion chamber defined in said tube.

2. A device as set forth in claim 1, including radial portions in circumferentially spaced relation relative to the inner end portion of said tube holding the latter in centered spaced relationship to the wall of said casing while allowing air flow from the bulb into the space bee tween the tube and casing to the air inlet opening in the wall of the tube.

3. A device as set forth in claim 1, wherein the air inlet opening is located near the outer end of said tube, whereby the air delivered to said tube from said bulb flows nearly the full length of said tube and casing therebetween to cool off said parts.

4. A device as set forth in claim 1, wherein said air inlet opening is one of a plurality of circumferentially spaced openings provided in said tube near the outer end thereof, whereby the air delivered to said tube from said bulb flows nearly the full length of said tube and casing therebetween to cool off said parts substantially uniformly.

5. A device of the character described, comprising an elongated tubular casing of uniform diameter adapted to be held in one hand and having a tapered portion on :one end terminating in a reduced neck portion, a bulb of compressible resilient material mounted on and adapted to deliver air under pressure to said neck por tion and having an outwardly seating check valve controlling its air intake and discharge, said check valve opening inwardly to admit fresh air into said bulb and closing outwardly upon compression of said bulb whereby to cause air flow in one direction into said casing from said bulb, an elongated, combustion chamber defining tube mounted inside said casing in spaced non-conducting relation thereto closed at its inner end which has abutment with the tapered portion of the casing to limit endwise movement inwardly of said tube and having a flared portion on its outer end fitting closely inside the outer end of said casing, said casing having an inwardly projecting annular edge on its outer end engaging the outer end of said flared portion of said tube and sealing the joint therebetween at the outer end of said casing, said tube having an air inlet opening in the wall thereof, and a removable nozzle having a tapered portion entered in the flared outer end portion of said tube closing said tube and having a longitudinal bore defining a relatively restricted discharge orifice in the outer end portion thereof and an enlarged inner end portion, communicating with said orifice and with the combustion chamber and defining a holder for one end portion of an elongated combustible material, such as a cigaret, for insertion of one end of the combustible material to be supported by and to extend inwardly from said holder into the combustion chamber defined in said tube.

6. A device as set forth in claim 5, including radial portions in circumferentially spaced relation relative to the inner end portion of said tube holding the latter in centered spaced relationship to the wall of said casing while allowing air flow from the bulb into the space between the tube and casing to the air inlet opening in the wall of the tube, the air inlet opening being located near the outer end of said tube, whereby the air delivered to said tube from said bulb flows nearly the full length of said tube and casing therebetween to cool off said parts.

7. A device as set forth in claim 5, including a gasket of compressible resilient material on said nozzle wedgingly engaging in the flared portion of said tube to seal the joint therebetween.

8. A device of the character described, comprising an elongated tubular casing adapted to be held in one hand, means to supply air under pressure communicating with one end thereof, said means causing air flow in one direction into said end of said casing, an elongated, com

tbustion chamber defining tube mounted inside said cas ing in spaced nonconducting relation thereto closed at its inner end and having an open outer end in sealed relationship annularly thereof to the other end of said casing, said tube having an air inlet opening in the wall thereof, and a removable nozzle closing the open end ofsaid tube and having a longitudinal bore defining a relatively restricted jet orifice in the outer end portion thereof and an enlarged inner end portion communicating with said jet orifice and with the open outer end of said combustion chamber defining tube defining a holder for one end portion of an elongated combustible material, such as a cigaret for insertion of one end of the combustible material to be supported by and to extend inwardly from said holder into the combustion chamber.

9. A device as set forth in claim 8, including radial portions in circumferentially spaced relation relative to the inner end portion of said tube holding the latter in centered spaced relationship to the wall of said casing.

10. A device as set forth in claim 8, wherein the air inlet opening is located near the outer end of said tube, whereby the air delivered to said tube from said air supply means flows nearly the full length of said tube and easing therebetween to cool off said parts.

11. A device as set forth in claim 8, wherein said air inlet opening is one of a plurality of circumferentially spaced openings provided in said tube near the outer end thereof, whereby the air delivered to said tube from said air supply means flows nearly the full length of said tube and easing therebetween to cool off said parts substantially uniformly.

(References on following page) References Cited in the file of this patent 573,675

UNITED STATES PATENTS 16,516 Whitaker Ian. 27, 1857 42,380 Kidder Apr. 19, 1864 5 68,188 Hamilton Aug. 27, 1867 421,922 Fyfe et a1. Feb. 25, 1890 10,408

6 Luther Dec. 22, 1896 Lauber Mar. 2, 1897 Mellinger et a1 Oct. 10, 1950 FOREIGN PATENTS Great Britain May 8, 1897 

